This invention relates to window arrangements having a window pane slidable in a guide and having a control for moving the window pane.
In a preferred application of the invention, i.e. a side window arrangement for a motor vehicle, the friction between a window pane and the lateral guides for the pane requires comparatively large driving forces for the sliding motion of the pane in the guides. These driving forces must be exerted by an electric motor in the case of motor actuation of the pane and otherwise by a manually rotated hand crank. For a side window arrangement in a motor vehicle, the pane executes vertical movements as a rule and the drive system must be designed to supply the forces required not only to overcome the maximum friction, which is dependent on temperature and aging, but also to produce the desired window movements in winter when the pane is icy or when the pane is frozen to the guides.
In the introduction to European Published Application No. 64 43 50, which deals with the reduction of squeeze noises and consequent vibration during the movement of a window pane, known window seals for window panes in doors of motor vehicles are described in which the contact pressure of the seal with the pane is reduced during movement of the pane thus reducing the expenditure of motor power to move the pane. However, the described arrangement is not usable in the case of the icing of the window pane as described above. Furthermore, the proposed reduction of contact pressure of the seal with the pane produces a danger of leakage.
Further prior art relating to friction arrangements is classified in Group G 1283/06 of the International Patent Classification but that prior art relates to the reduction of friction by vibration for quite different objects such as measuring instruments.